The present invention relates to the indication of charging information at a mobile station supporting unstructured supplementary service data according to the preamble of claim 1.
Further, the present invention relates to a digital cellular communication network comprising at least one public land mobile network according to the preamble of claim 10.
Finally, the present invention relates to a method to provide charging specific information in a digital cellular communication network supporting unstructured supplementary service data messages according to claim 19.
Digital cellular communication systems meanwhile are in common use. One example for such a digital cellular communication system is the pan-European mobile telecommunication network GSM for which technical specifications have been elaborated by the European Telecommunication Standards Institute ETSI. Digital cellular communication systems allow its users to initiate and receive calls and services, respectively, at any geographical area within the radio coverage of the home public land mobile network HPLMN operated by the network operator selected by the subscriber and also within the radio coverage area of partners of the network operator providing services within the home public land mobile network, HPLMN, i.e. network operators having a roaming agreement with the HPLMN-network operator.
Basic sub-systems for the architecture of a digital cellular communication network are provided to establish services in a public land mobile network PLMN service area of a single network operator. These sub-systems comprise a base station sub-system BSS, a network and switching sub-system NSS and an operational sub-system OSS. The base station sub-system BSS provides and manages transmission paths between mobile stations MS and the network and switching sub-system NSS. The network and switching sub-system NSS manages communications and connections to the mobile stations MS.
FIG. 9 shows further components being related to the network and switching sub-system NSS, the base station sub-system BSS and the mobile station MS, respectively. In particular, FIG. 9 shows a public land mobile network PLMN that may either be the home public land mobile network HPLMN or the visiting public land mobile network VPLMN of a subscriber.
To achieve a link between two different PLMN service areas there is provided a gateway mobile service switching centre GMSC that serves to determine specific locations of a mobile station MS in the digital cellular communication system and to route calls towards a mobile station MS. In addition, an even more important task of the gateway mobile service switching centre GMSC is to connect to other networks.
As shown in FIG. 9, the gateway mobile service switching centre GMSC is connected to a functional unit called home location register HLR where two types of information are stored, i.e. subscriber information and mobile information to allow incoming calls to be routed to the mobile station MS. Any administrative action by the network operator with respect to mobile station data is carried out in the home location register HLR.
To route a call to a mobile station MS the gateway mobile service switching centre GMSC is also connected to a mobile service switching centre MSC through which the mobile station MS can obtain a service. The mobile service switching centre performs the necessary switching functions required for mobile stations MS covered by this mobile service switching centre MSC. Also, the mobile service switching centre MSC monitors the mobility of its mobile stations MS and manages necessary resources required to handle and update the location registration procedures.
As outlined above and shown in FIG. 9 the public land mobile network HPLNM/VPLMN comprises a plurality of mobile service switching centres MSC and respective service areas each covering a predetermined number of basic cells wherein a mobile station can move. To this end each mobile service switching centre MSC is connected to a visitor location register VLR. The visitor location register VLR is a functional unit that dynamically stores mobile station information, such as the location area in case the mobile station is located in the service area covered by the visitor location register VLR. When a roaming mobile station MS enters a service area assigned to a specific mobile service switching centre MSC the mobile service switching centre MSC informs the associated visitor location register VLR about the mobile station MS.
In addition, the base station sub-system BSS corresponds to physical equipment providing radio coverage to the above-mentioned cells which are approximately hexagonal geographical regions in FIG. 9. Each base station sub-system BSS contains equipment required to communicate with the mobile station MS.
In the digital cellular telecommunication network system there are three types of logical channels: traffic channel, control channel, and cell broadcast channel. The traffic channels are used to transmit user information like speech or data. The control channels are used to transmit control and signalling information. Finally, the cell broadcast channels are used to broadcast user information from a mobile services switching centre MSC to the mobile station MS listening in a given basic cell/basic service area.
Using the architecture of the digital cellular telecommunication network system outlined above, there may be provided a group of communication capabilities to the subscribers. The basic telecommunication services provided in the GSM digital cellular telecommunication network system are divided into three main groups: bearer services, teleservices, and supplementary services.
The bearer services give the mobile station MS the capacity required to transmit appropriate signals between certain user network interfaces such as data services, alternate speech/data, speech followed by data, clear 3.1 kHz audio service and support of automatic request for retransmission technique for improved error rates.
The teleservices provide the mobile station MS with necessary capabilities including terminal equipment functions to communicate with other mobile stations, e.g., short message services or message handling and storage services.
Finally, supplementary services modify or supplement basic telecommunication services and are provided with or in association with the basic teleservices. Such supplementary services comprise, e.g., number identification services, call offering services, call completion services, multi party services, or call restriction services.
In order to be able to deliver an incoming call to a mobile station on the basis of these different services it is necessary to know the location of the mobile station MS at any time. This is achieved through continuous data exchange between the mobile station MS and the base station sub-system BSS in the service area where the mobile station is located. Thus, the digital cellular telecommunication network system keeps track of the mobile station MS and stores location information in the respective home location register HLR and visitor location register VLR.
Generally, charges and tariffs for calls in cellular digital communication systems described so far are to a large extent not related to technical specifications but dealt with by system operators.
Usually the calling mobile station or the subscriber mobile station may receive information in real time about call-related costs through the Advice of Charge AoC supplementary service specified in ETSI Advice of Charge AoC supplementary services, GSM Recommendation 02.86, November 1996.
Firstly, this feature may be related to an approximate indication to what will appear on the bill in case a call would be finished at the time of the Advice of Charge. Charges are indicated for the call in progress when originating at the mobile station or for the roaming leg only when the call terminates at the mobile station. Usually, the mobile station MS receives at the beginning of each call a message as Charge of Advice Information defining the rate at which the call will be charged, time dependence, data dependence, and unit increments, see GSM 02.24, ETS 300 918, xe2x80x9cDigital cellular telecommunications system, Phase 2+; General on supplementary servicesxe2x80x9d. The mobile station MS then indicates appropriate charges even when roaming based on HPLMN units. Also where applicable, the volume charge per packet data service is indicated in addition to the normal time dependent and incremental charges.
Secondly, the Advice of Charge supplementary service may be used to indicate the charge that will be made for the use of telecommunication services. This aspect is intended for aspects where the user is generally not the subscriber but is known to the subscriber and pays the subscriber rather than the service provider. Here, the charge is based as closely as possible on the charge that will be levied on the subscriber""s bill in the home puplic land mobile network HPLMN.
However, in both cases accuracy of the Advice of Carge AoC supplementary service is a problem, e.g., in an international multi-operator environment when a user is roaming out of the network which holds his subscription. In particular, the roaming of a mobile station MS means that the PLMN handling a call and issuing the toll ticket is not necessarily the one that bills the subscriber such that the call charge and the bill charge are different, e.g., due to different currencies. Further, any charges for non-call related transactions and for certain supplementary services, e.g., call forwarding are not indicated.
Further, with existing mobile stations MS charging estimates are derived only on the basis on the time elapsed and indicate only the time used for a service but not the actual costs levied on the user of the mobile station MS.
Still further, the functionality being related to the Advice of Charge AoC supplementary service must be implemented to the mobile station MS, thus increasing the complexity and the costs for mobile stations. Therefore, no charge information will be provided to the user in case the mobile station MS does not support the Advice of Charge functionality and in particular in the second case the telecommunication service is prevented at all.
In view of the above, the object of the invention is to provide improved overview on service charges for a subscriber to a digital cellular communication network.
According to the present invention this object is achieved through a mobile station having the features of claim 1.
Therefore, it is possible to provide charging information without any impact on the hardware of the mobile station, i.e. without any extra hardware support required, e.g, for the Advice of Charge AoC supplementary service. The reason for this is that charging information may be provided through a network node of the digital cellular communication network wherein the mobile station is roaming so that charging information related functionality must not be provided at all in the mobile station.
Further, the provision of charging information is not restricted to the actual time used for a certain service. As more detailed information on the kind of service, on the amount of data transferred, on the location of the calling or called party may be transferred, a detailed estimate on the actual costs may be displayed to the user of the mobile station.
According to a preferred embodiment of the invention the charging indication information means is adapted to receive charging information at the beginning of a service, and then to terminate the transfer after confirmation of receipt thereof. Only in case charging information changes during a service the transfer charging information is re-established. This embodiment of the present invention is particularity adapted to long duration services where in addition the amount of unstructured supplementary service data messages should be minimized. Further, the dynamic adaptation of charging information allows for improved estimation accuracy, in particular during roaming between different charging areas.
According to a further preferred embodiment of the present invention the charging information is provided continuously from a network node to derive an estimate of service charges on the basis of time-specific, location-specific, or service-specific criteria, respectively. Therefore, the use of unstructured supplementary service data messages allows the provision of charging information without any particular implementation overhead at the mobile station side.
According to a further preferred embodiment of the invention the charging indication information means is adapted to simultaneously establish the transfer of unstructured supplementary data messages to indicate charging information provided through the local operator and charging information processed offline. This embodiment is particularity well adapted to a case where a user of a mobile station is roaming abroad with respect to the country where his home public land mobile network HPLMN lies. Here, it is possible to indicate to the user of the mobile station that part of the overall costs for a service will be charged to him and also to indicate an exact estimate of the costs for a service during roaming.
According to a further preferred embodiment of the present invention the charging information is received before establishment of a service to derive an estimate of service charges on the basis on time-specific, location-specific, or service-specific criteria, respectively. Therefore, the use of unstructured supplementary service data messages allows the provision and retrieval of charging information also in non-operative states of the mobile station, e.g., out of call.
According to a further preferred embodiment of the present invention the mobile station comprises location information indicating means adapted to identify a location information for a cell where the mobile station is currently roaming. The location information may then be output to a charging application via the unstructured supplementary service data dialogue means. This embodiment, too, takes into account that in case a calling mobile station has its home public land mobile network HPLMN in a different country than the called mobile station an overhead may appear in the routing if the called mobile station is actually roaming in the country of the home public land mobile network HPLMN of the calling mobile station. In such a case the service may be routed back and forth between the two home public land mobile networks HPLMN instead of using a national or even local link. To avoid this undesireable situation it is proposed to incorporate the location of the calling mobile station and the called mobile station into the provision of charging information. Preferably, the related location information is automatically updated during roaming of the calling and called mobile station to enable a call back feature in the mobile station MS.
Further, according to the present invention there is provided a digital cellular communication network having the features of claim 10 and 14, respectively.
The architecture of the inventive digital cellular communication network allows improved charging information without impact on the architecture of the mobile stations roaming therein. Corresponding to user preferences it is possible to select communication times that are cheaper, in particular for services not requiring immediate delivery, e.g., suplementary short message services SMS. Thus, the operator may attract calls by offering lower tariffs in low usage times.
Preferably, charging information is sent at regular intervals using the unstructured supplementary service data messages for automatic display at the mobile station so that the customer is continuously aware of the costs for services provided.
According to a further preferred embodiment of the present invention the mobile station MS roaming in the inventive digital cellular communication network is implemented as outlined above to handle local operator generated charging information and charging information processed offline, e.g., during call forwarding to the called mobile station MS. This embodiment of the present invention takes into account that the forwarding of services to a called mobile station and the charging therefore is usually executed in network nodes which therefore may best estimate related charging costs. Therefore, the mobile stations MS should only be adapted to receive the correct charging information, however, without any overhead to carry out an estimation of the charging costs in the mobile station MS itself. Further, it is possible to minimize the communication necessary for the indication of charging information since related tasks are executed at places where the information is immediately available.
Finally the advantages outlined above are also achieved with a method to provide charging specific information in a digital cellular communication network supporting unstructured supplementary service data messages according to claim 16.